Conventional techniques in relation to Group III nitride compound semiconductor light-emitting devices in which a reflective layer is formed on the back side of a substrate in order to obtain light reflection effects and in relation to methods for producing such devices are disclosed in, for example, Japanese Patent Application Laid-Open (kokai) No. 11-126924 entitled “Method for Producing Gallium Nitride Compound Semiconductor Devices” and Japanese Patent Application Laid-Open (kokai) No. 11-126925, 5-129658, and 11-261112.